Fabianski has been rewarded for an excellent first season at Swansea, keeping 13 clean sheets following his free transfer from Arsenal last summer.
The 30-year-old Poland international had attracted interest from Serie A giants Roma but Swansea have moved quickly to tie him down to a new deal.
"It's protection for the club because players like him are assets, but the way I look at it is players sign these new deals because they have earned them and deserve them," Swansea manager Garry Monk said ahead of his side's Barclays Premier League opener at Chelsea on Saturday.
Fabianski made only 78 appearances in seven seasons at Arsenal but missed only one league game last term as Swansea finished in their highest Premier League of eighth.
Only Manchester City's England goalkeeper Joe Hart kept more clean sheets in the top flight and Fabianski was named Players Player and Best Newcomer of the season at Swansea.
"I am very happy here
Right from the very first day, everyone has been very nice to me and they've helped me settle in quickly," Fabianski told his club's official website.
"It's nice to hear your name being linked with clubs because it means you must be doing your job well
But, in my mind, I want to continue here at Swansea
"There's still a lot of work to be done, and I was always focused on this place rather than thinking about somewhere else
Nothing has ever crossed my mind other than Swansea.
"It's another chapter for me
I must forget about what happened last year as I am focusing and preparing for the new season."
Fabianski joins defender Neil Taylor, midfielder Jonjo Shelvey and manager Monk in penning new contracts this summer
while forwards Andre Ayew and Eder, left-back Franck Tabanou and goalkeeper Kristoffer Nordfeldt have been recruited as Swansea seek to build on last season's success.
"If we can achieve the things we talked about in pre-season then we can compete for a high position in the league," Fabianski said.
"All the ingredients are there
The team stayed together and we have improved the squad, which has been a massive positive from this summer."
Source : PA
Source: PA